Detergent compositions containing carboxy-esters of hydroxybenzimidazolyl-stilbenes



DETERGENT COMPOSITIONS CONTAINING CAR- BOXY-ESTERS OFHYDROXYBENZIMIDAZO- LYL-STILBENES Nathan N. Crounse, Cincinnati, Ohio,assignor to Sterling Drug Inc., New York, N.Y., a corporation ofDelaware No Drawing. Original application Apr. 2, 1956, Ser. No.575,353, now Patent No. 2,878,248, dated Mar. 17, 1959. Divided and thisapplication June 20, 1958, Ser. No. 745,236

12 Claims. (Cl. 252-117) N a CH C 31 CH C O \N/ FORMULA r where R R Rand R are radicals of the class consisting of hydrogen, lower alkylcontaining 1-4 carbon atoms, lower alkoxy containing 1-4 carbon atoms,and halo, and Y and Y are radicals of the class consisting of hydrogen,lower alkyl containing 1-6 carbon atoms, hydroxy-lower alkyl containing2-6 carbon atoms, 2- hydroxy 3 sulfopropyl, hydroXy-oxaalkyl containing3-15 carbon atoms, carboXy-lower alkyl containing 2-6 carbon atoms,cyano-lower alkyl containing 3-6 carbon atoms, allyl, methallyl, andmonocyclic aralkyl containing 7-11 carbon atoms. Thebenzimidazolylstilbenes of the above formula are water-insolublecompounds which are highly useful as whitening and brightening agents,for instance in the form of dispersions in aqueous media, such as insoap and synthetic detergent composit-ions, for the treatment of whiteand colored textiles.

I have now discovered that certain of the benzimidazolylstilbenesdescribed in my said prior application, namely those containing one ormore alcoholic hydroxyl groups in the radicals Y and Y can be convertedto novel carboxy-esters afiording for some purposes valuable advantagesas whiteningand brightening agents in tates Patent F the treatment ofthreads, sheets, films, filaments, textile fabrics and the like, as wellas in the manufacture of paper, varnishes, inks, coatings, and plastics.

Broadly speaking, the new compounds of the instant invention arecarboxy-esters of dicarboxylic acids withhydroxy-benzimidazolylstilbenes having the structural formula FORMULA Irwhere R R R .and R are radicals of the class consisting of hydrogen,lower alkyl containing 1-4 carbon atoms, lower alkoxy containing l-4carbon atoms, and halo, Y is a radical of the class consisting ofhydrogen, lower alkyl containing 1-6 carbon atoms, hydroxy-lower alkylcontaining 2-6 carbon atoms, 2-hydroxy-3-sulfopropyl, hydroxy-oxaalkylcontaining 3-15 carbon atoms, carboxy-lower alkyl containing 2-6 carbonatoms, cyanolower alkyl containing 3-6 carbon atoms, allyl, methallyl,and mono-cyclic aralkyl containing 7-11 carbon atoms, and Y is a memberof the class consisting of hydroxy-lower alkyl containing 2-6 carbonatoms, ,2- hydroxy-3-sulfopropyl, and hydroxy-oxaalkyl containing 3-15carbon atoms. It will be appreciated that the radicals R R R R and Y areidentical respectively with the corresponding radicals as defined in US.Patent 2,838,504, issued June 10, 1958, and thatY represents thehydroxyl-containing radicals Within the definition of Y in the saidco-pending application. More particularly, the carboxy-esters of myinvention are those which can be prepared by interaction of cyclicanhydrides of aromatic, aliphatic, and cycloaliphatic 1,2-dicarboxylicacids with the hydroxy-benzimidazolylstilbenes of Formula II; in thisreaction the alcoholic hydrogen of the hydroxy-benzimidazolylstilbene isreplaced by a carboxycarboxylic acyl radical of the structurebenzimidazolylstilbenes. Thus, in a preferred aspect,'the

Patented May 24, 1960 I i r 3 present invention relates to the newcarboxy-esters having the structural formula Rs I V c I FORMULA IIIwhere R, R R and R are radicals of the class consisting of hydrogen,lower alkyl containing 1-4 carbon atoms, lower alkoxy containing 1-4carbon atoms, and halo, Z is a radical of the class consisting ofhydrogen, lower alkyl containing 1-6 carbon atoms, carboxy-lower alkylcontaining 2-6 carbon atoms, cyano-lower alkyl containing 3-6 carbonatoms, allyl, methallyl, monocyclic aralkyl containing 7-11 carbonatoms, acyloxylower alkyl wherein lower alkyl contains 2-6 .carbonatoms, 2-acyloxy-3-sulfopropyl, and acyloxy-oxaalkyl wherein oxaalkylcontains 3-15 carbon atoms, and Z is a radical of the class consistingof acyloxy-lower alkyl wherein lower alkyl contains 2-6 carbon atoms, 2-acyloxy-3-sulfopropyl, and acyloxy-oxaalkyl wherein oxaalkyl contains3-15 carbon atoms, said acyloxy being defined in each instance in thedefinitions of Z and Z by the formula HOOC-A--COO-, where A is theresidue of an acid of the group consisting of aromatic l,2 -dicarboxylicacids containing 8-20 carbon atoms,

aliphatic 1,2-dicarboxylic acids containing 4-22 carbon atoms, andcycloaliphatie 1,2-dicarboxy1ic acids containing 7-8 carbon atoms. Thepreparation and properties of the hydroxy-benzimidazolylstilbenes(Formula II) employed as starting materials in the instant invention aredescribed in detail in my US. Patent 2,838,504, issued June 10, 1958. Ifdesired, a. pure hydroxy-benzimidazolylstilbene can be used; however, Ihave found that is frequently advantageous, especially from an economicstandpoint, to employ'a. mixture of benzimidazolylstilbenes as thestarting material. Thus, there can be used either a mixture of two ormore hydroxy-benzimidazolylstilbenes (Formula II), or a mixtureconsisting chiefly of one or more 'hydroxy-benzirnidazolylstilbenes(Formula II) with a minor'p'roportion of one or more hydroxyl-freebenzirnidazolylstilbenes within the general Formula I above. The acidanhydride starting materials employed in the preparation of mycarboxy-esters are the cyclic anhyanhydride; alkylsuccinic anhydrides,such as methylsuccinic anhydride, dimethylsuccinic anhydride,dodecylsuccinic anhydride, and octadecylsuccinic anhydride;alkenylsuccinic anhydride, such, as allylsuccinic anhyd'ride,decenylsuccinic anhydrides, dodecenyisuccinic anthe ultraviolet region.

hydrides, and octadecenylsuccinic anhydrides; aralkylsuccinicanhydrides, such as benzylsuccinic anhydride; maleic anhydride;alkylmaleic anhydrides, such as methylmaleic anhydride; andaralkylmaleic anhydrides, such as benzylmaleic anhydride. Phthalicanhydrides are the preferred acid anhydride starting materials.

The process of interacting the hydroxy-benzimidazolylstilbene with thecyclic dicarboxylic anhydride is conveniently carried out by employingapproximately one mole of the acid anhydride per equivalent of hydroxyldesired to be esterified in the hydroxy-benzimidazolylstilbene,preferably, approximately one mole of acid anhydride is employed permole of monohydroxy-benzimidazolylstilbene and two moles of acidanhydride per mole of dihydroxyand polyhydroxy-benzimidazolylstilbenes.The esterification proceeds readily when the two reactants are heatedtogether, advantageously in a solvent and in the presence of an organicbase; it is usually sulficient to heat the mixture at IOU- C. for aboutthirty minutes to one hour. The reaction mixture is then poured intoacidified water, and the precipitatethus formed, which is the desiredcarboxy-ester of the hydroxy-benzimidazolylstilbene, is collected on afilter and washed. Sometimes, it is convenient to employ an excess ofthe acid anhydride as the reaction solvent, for example when esterifyinga monohydroxy-benzimidazolylstilbene or when diesterifying ai.dihydroxy-benzimidazolylstilbene. In these cases, the mixture of thetwo reactants is heated to-fusion to facilitate complete reaction.

Instead of employing a single acid anhydride in the reaction, there canbe used a mixture of cyclic dicarboxylic acid anhydrides, in appropriatetotal quantity. Also, whenmore than one hydroxyl group in thehydroxybenzirnidazolylstilbene is to be esterified, the reaction can becarried out step-wise, one molecular equivalent of acid anhydride at atime, and theacid anhydride can be the same or different in each step,so that mixed carboxyesters can be readily prepared if desired.

In general, my new carboxy-esters are yellow or greenish-yellowcrystalline solids which are slightly soluble in dimethyl sulfoxide,Z-methoxyethanol, and 2- ethoxyethanol, and are insoluble in hydrocarbonsolvents. The compounds form salts when mixed with organic or inorganicbases, and many of these salts are either readily soluble in water ormore soluble in water than the free acid form of the carboxy-ester.Thus, the solubility of the carboxy-esters in solvent media such aswater or aqueous lower alkanols is considerably enhanced by the presenceof bases, for instance sodium hydroxide, potassium hydroxide, ammonia,pyridine, triethanolamine, 2,2-bis(hydroxymethyl) -2aminoethanol, andthe like. Many of the carboxy-esters are easily soluble in diluteaqueous ammonia solution.

When the new compounds of my invention are dissolved in aqueous media,they fluoresce blue-white under ultraviolet light and show a wide rangeof absorption in Increasing the water-solubility of whitening andbrightening agents ordinarily has an adverse eflFect on theirsubstantivity to many synthetic fibers. Surprisingly, however, my newcarboxy-esters,

which have enhanced solubility in aqueous media as compared with thecorresponding hydroxy-benzimidazolylstilbene starting materials (FormulaII), are substantive to a wide variety of natural and synthetic fibers,for example, cotton, cellulose acetate, viscose rayon, nylon, and silk,and are absorbed by such fibers even from very low concentrations inaqueous solutions. The compounds have relatively high stability tosunlight, soap, synthetic detergents and chlorine-containing bleachingagents. The substantivity properties of the carboxy-esters are in factclosely similar to those of the hydroxy-benzirnidazolylstilbenes(Formula II), which are substantially water-insoluble.-

The above-described properties of my new compounds adapt them especiallyto use in aqueous solutions as whitening and brightening agents intreating fabrics to neutralize the yellowness in White textiles or toenhance the brilliance of colored textiles. In such utilization, therelatively high resistance of my compounds to chlorine bleaching and tolight are valuable advantages.

The treatment of textile fabrics with my compounds is readily carriedout by conventional procedures. Thus, for example, an aqueous solutioncontaining about 0.0001 to 0.5% by weight of the carboxy-ester, or asalt thereof such as an ammonium salt, is applied to the fabric, whichabsorbs the fluorescent compound and is whitened or brightenedbeneficially thereby. This application of the compound can beconveniently carried out in conjunction with a washing or rinsingoperation.

The solutions are readily formed, for example, by dissolving thecompound in water alone or, if the watersolubility is not suilicientlyhigh, in water containing a small amount of an organic or inorganicbase. In some cases, a non-aqueous solvent such as Z-methoxyethanol or2-ethoxyethanol, optionally containing a small amount of an organic basesuch as triethanolamine, can be employed. The solutions thus obtainedcan be mixed in desired quantity with a solid or liquid soap orsynthetic detergent.

A preferred mode of using and marketing the compounds of my invention isby incorporating them into solid or liquid soaps and syntheticdetergents in an appropriate concentration, for example 0.02 to 0.5% ofthe whitening and brightening agent by weight. The synthetic detergentsused are water-soluble synthetic organic anionic and non-ionicdetergents (for example, see McCutcheons Synthetic Detergents,McNair-Dorland Company, New York, N.Y., 1950, pages 120-174) such asorganic sulfates and sulfonates, for instance sodium lorol sulfate, andsodium (higher alkyl) benzenesulfonates, andtert-dodecylmercaptopolyethoxyethanol (Nonic 218). Soaps and anionicdetergents are of course frequently available in admixture with eachother or with smaller amounts of inorganic detergents or builders suchas tetrasodium pyrophosphate, sodium tripolyphosphate, sodiummetasilicate, sodium borate and sodium perborate, and these mixtures canalso be employed in utilizing my invention.

My invention is illustrated by the following examples without, however,being limited thereto.

EXAMPLE 1 (1i) 4 [I-(Z-hydroxyethyl) benzimidazol-Z-yl] -4-{1-[2-(2-hydr0xyeth0xy)ethyl] benzimidazol-2-yl}stilbene A mixture of4,4-bis(benzirnidazol-Z-yl) stilbene, 180 ml. of Z-methoxyethanol, and14.2 g. of a 50% aqueous solution of sodium hydroxide was heated at76-86 C.

and 30 g. of ethylene oxide was passed into the resulting solution overa period of one hour. During this period, a solid precipitated from thesolution. To the reaction mixture there was then added dropwise 1500 ml.of warm (50 C.) water. The mixture was then filtered and the solid thuscollected was washed with Water to free it of alkali. There was thusobtained 39 g. of product which consisted chiefly of4-[1-(Z-hydroxyethyl)benzimidazol-2- yl] 4{1-[2-(2-hydroxyethoxy)ethyl]benzimidazol-2- yl} stilbene (Formula II: Y=HOCH CH R R R and R =H). It was found that this component could beseparated from the mixture in pure form by repeated recrystallization ofthe product from 95% ethanol. The yield of the pure compound, alemon-yellow crystalline solid melting at 280-285 C., from the mixturein this manner was about 30%.

Analysis.Calcd.: N, 10.28%; C, 74.8%; H, 5.93%. Found: N, 10.47%; C,74.25%; H, 5.90%.

5.0 g. of the mixture of hydroxyethylated products obtained as describedin part A above, 2.0 g. of maleic anhydride, 50 ml. of dimethylsulfoxide, and 5 ml. of pyridine were heated together at -120" C. forthirty minutes. The reaction mixture was mixed with 500 ml. of water andmade barely acid to Congo red paper by addition of hydrochloric acid.The mixture was filtered and the solid thus collected was washed free ofhydrochloric acid with water. There was obtained in this manner 7.0 g.of product which melted at 155-157 C. It consisted chiefly of the bis(acid maleate) of 4-[1-(2-hydroxyethyl)benz.imidazol-2 yl] 4{1-{2-(2-hydroxyethoxy)ethyl]benZimidazol-2-yl}stilbene (Formula III:

Z =HOOCCH=CH--COO--CH CH Z =HOOCCH=CH-COO 1K R R and R =H). The productwas readily soluble in Z-methoxyethanol containing a small amount oftriethanolamine.

EXAMPLE 2 Bis(acid phthalate) of 4-[1-(2-hydroxyethyl)benzimidazol 2yl]-4'-{1-[2-(2-hydroxyethoxy)ethyllbenzimidaz0l-2-yl}siilbene 10.92 g.of crude 4-[1-(2-hydroxyethyl)benzimidazol- 2 yl] -4-{ 1- [2(Z-hydroxyethoxy) ethyl] benzimidaZol-2- yl}stilbene obtained asdescribed above inExample 1(A), 7 .0 g. of phthalic anhydride, 40 ml. ofdimethyl sulfoxide, and 5 ml. of pyridine were heated together at 100 C.for thirty minutes. The reaction mixture was stirred with 500ml. ofwater having dissolved therein 7 ml. of concentrated (about 37%)hydrochloric acid. The insoluble product was collected on a filterpaper, washed free of hydrochloric acid with water, and dried. There wasthus obtained 15.9 g. of product which melted at 131132 C. It consistedchiefly of the bis(acid phthalate) of '4-[1-(2-hydroxyethyl)benzirnidazo-2-yl] 4 {1-[2-(2-hydroxyethoxy)ethyl]benzimidazol-2-yl}stilbene(Formula III:

R R R and R H). The product was soluble in dilute aqueous ammoniasolution, dilute aqueous triethanolamine solution, and Z-methoxyethanol.

By neutralizing the product with two equivalents of2,2-bis(hydroxymethyl)-2-aminoethanol, there was obtained thecorresponding bis-amine salt.

Analysis.-Oalcd. C, 64.3%; H, 5.76%; N, 7.75%; O, 22.2%. Found: C,63.27%; H, 6.28%; N, 7.85%; O (by diiference), 22.6%.

The above bis(acid phthalate) was flso obtained in substantially thesame yield when 40 cc. of N,N-dimethy'laniline was used as the reactionsolvent instead of the mixture of dimethyl sulfoxide and pyridine.

The same bis(acidphthalate) was also obtained when an excess of phthalicanhydride was used as a solvent and the reaction was carried out byfusing a mixture of the two reactants.

EXAMPLE 3 Acid phthalates of 4 [1 -(2hydr0xyethyl benzimidazol-Z- yl]4-{1-[Z-(Z-hydroxyethoxy) ethyl] benzimidazol-Z- yl}stilbene A mixtureof 54.2 g. of crude 4-[1-(2-hydroxyethyl) benzimidazol 2yl]-4'-{1-[2-(Z-hydroxyethoxy)ethyl] benzimidazol-2-yl}sti1bene, 15.5 g.of phthalic anhydride, 200 ml. of dimethyl sulfoxide, and 20 ml. ofpyridine was heated at 100-120 C. for thirty minutes. The reactionmixture was stirred in a solution of 35 ml. of concentrated hydrochloricacid in 2000 ml. of water. The insoluble product was collected on afilter, washed free of hydrochloric acid with water, and dried. Therewas thus obtained 67.0 g. of product which melted at 242 C. It was amixture which consisted chiefly of the mono acid phthalates 1 of4-[1-(2-hydroxyethyl)benzimidazol-Z-yl]- 4{1-E2-(2-hydroxyethoxy)ethyl]benzimidazol-2-yl}stil bene (derivativeswhere in Formula II only one of the hydroxylic hydrogens is replaced bythe acyl radical ortho- HOOC-C H --CO; and R R R and R =H).

EXAMPLE 4 The starting material for this example was dihydroxypropylated4,4'-bis(benzimidazol-Z-yl)stilbene prepared as described in Example 28of US. Patent 2,838,504, issued June 10, 1958, and interacted withsufficient ethylene oxide to ensure that no unreacted4,4-bis(benzimidazol- 2-yl)stilbene remained in the product. The productconsisted chiefly of 4-benzimidazol-2-yl-4-{1-[2-hydroxy-3-(2,3-dihydroxypropoxy)propyl]benzimidazol-2-yl}stilbcne and lesseramounts of and N-hydroxyethylated derivatives thereof together withsmall amounts of 4-(benzimidazol 2yl)-4-'E1-(2-hydroxyethyl)benzimidazol-2-yl)- stilbene and4(-benzimidazol-2yl)-4'-{l-[2-(2-hydroxyethoxy) ethyl lbenzimidazol-2-y1}stilbene.

27.3 g. of the above-indicated starting material, 100 ml. of dimethylsulfoxide, and 10 ml. of pyridine were heated together at 115120 C. forfive minutes to ensure that all of the solid had dissolved. There wasthen gradually added to the hot solution 15.5 g. of phthalic anhydrideover a period of about fifteen minutes. The reaction mixture was heatedat 115-120 C. for one hour, and then was cooled and stirred with amixture of 900 ml. of water, 17 ml. of concentrated hydrochloric acid,and 100 g. of ice. The mixture was filtered to collect the solidprecipitate, which was washed free of hydrochloric acid with water anddried. There was thus obtained 34.8 g. of product which melted at 153 C.with evolution of gas. The chief components of this mixture were acidphthalates of 4-(benZimidazol-2-yl)-4'-{1-[2- hydroxy-3-(2,3dihydroxypropoxy)propyl]benzimidazol- 2-yl}stilbene. It was soluble inammoniacal 95% ethanol and in triethanolamine.

EXAMPLE 5 Acid phthalates of dihydroxypropylated 4,4'-bis[5 (or 6)-meth0xy benzimidazol-Z-yll stilb ne When 30.0 g. of 4-[5(or6)-methoxybenzimidazol-2- yl] -4'-{ 1- [2hydroxy-3-(2,3-dihydroxypropoxy) propyll -5- (or6)methoxybenzimidazol-2-yl}stilbene, prepared as described in Example 19of US. Patent 2,838,504, issued June 10, 1958, is acylated with 15.5 g.of phthalic anhydride using a procedure similar to that described inExample 4 above, there are produced the acid phthalates of thishydroxy-benzimidazolstilbene.

EXAMPLE 6 chloric acid with water, and dried. There was thus obmaleateesters.

3 tained 43.3 g. of product which melted at 162-164" C. It consistedchiefly of a mixture of the bis(3-chloroph: thalate) and thebis(4-chlorophthalate) of 4-[1-(2-hydroxyethyl) benzirnidazol-Z-yl] 4'{1 [2-(2-hydroxyethoxy.) ethyllbenzimidazolr 2 yl}stilbene (Formula III:

R R R and R =H). The product was soluble in dilute aqueous ammoniasolution. I

EXAMPLE 7 Bz'stfacid tetrachlorophthalate) of 4 [1-(2-hydroxyethyl)-benzimidazol-2-yl] -4'-{1-[2- (2hydroxyethoxy)ethyllbenzimz'dazol-Z-yl}szilbene A mixture of 27.1 g. ofcrude 4-[1-(2-hydroxyethyl)- benzimidazol 2-y1]4-{1-[2-(2-hydroxyethoxy)ethyl]- benzimidazol-2-yl}stilbene, 28.6 g. oftetrachlorophthalic anhydride, ml. of dimethyl sulfoxide, and 10 ml. ofpyridine was heated at 100-420 C. for thirty minutes. The reactionmixture was mixed with a solution of 17 ml. of concentrated hydrochloricacid in- 1000 ml. of water. The insoluble product was collected on afilter, washed free of hydrochloric acid with-water, and dried. Therewas thus obtained 49.0 g. of product which melted at 186-188 C. Itconsisted chiefly of the bis(tetrachlorophthalate) of 4-[1-(2-hydroxyethyl) benzimidazol-Z-yll 4' {1 [2 (2-hydroxyethoxy)ethyllbenzimidazol-Z-yl} stilbene (Formula III:

R R R and R =H). The product was slightly soluble in dilute aqueousammonia solution.

EXAMPLE 8 Acid te lrachlorophthalates of 4-[5 (or 6)-chlor0benzimidazol-Z-yl] -4'-{1-[2-hydroxy-3-(2,3-dihydr0xprop0xy)-propyl] -5 (0r 6) -chlorobenzimidazol-Z-yl}stilbene 7 When 33.4 g. of4-[5(or 6)-chlorobenzimidazol-2yll- 4'-{ l- [2-hydroxy-3-( 2,3dihydroxypropoxy) propyl 5 (or 6)-chlorobenzimidazol 2 yl}stilbene(prepared as described in Example 20 of US. Patent 2,838,504, issuedJune 10, 1958) and 14.3 g. of tetrachlorophthalic anhydride areinteracted following a procedure similar to that described above inExample 7, there is obtained. a product consisting of a mixture of theacid tetrachlorophthalates of the hydroxy-benzimidazolylstilbene.

EXAMPLE 9 Mixed acid phthalate and acid maleate esters of 4-[1-(2-hydroxyethyl) benzimidazol-Z-yl] -4'-{1-[2-(2 hydroxyethoxy)ethyl]-benzimidazol-Z-yl}stilbene A mixture of 27.1 g. of4-[1-(2-hydroxyethyl)benzimidazol-2-yl]-4'-{1-[2 (2hydroxyethoxy)ethylJbenzimidazol-2-yl}stilbene, 100 ml. of dimethylsulfoxide, and 10 m1. of pyridine was heated to -120 C. and to the hotmixture there was added 7.5 g. of phthalic anhydride. The reactionmixture was stirred at 110-120" C. for five minutes, then 5.0 g. ofmaleic anhydride was added, and stirring and heating at 110-120 C. werecontinued for one hour. The reaction mixture was cooled and poured intoa solution of 17 ml. of concentrated hydrochloric acid in 1000 ml. ofwater. The insoluble precipitate was collected on a filter, washed freeof hydrochloric acid with water, and dried. There was thus obtained 37.7g. of product which melted at -462 C. It consisted of a mixture of thebis(acid phthalate), the bis(acid maleate), and the mixed acidphthalate-acid 95% ethanol.

The product was soluble in ammoniacal 9 EXAMPLE 10 Mixed acid phthalateand acid maleate esters of dihydroxypropylated 4,4'-bis[5 (r 6)-methylbenzimida'z0l- 2-yl1stilbene By acylating 30 g. of thedihydroxypropylated 4,4-bis- [(0r 6)-methylbenzimidazol-2-yl]stilbenedescribed in the latter portion of Example 18 of U.S. Patent 2,838,504,issued June 10, 1958, with 7.5 g. of phthalic anhydride and then with5.0 g. of maleic anhydride, using a procedure similar to that describedabove in Example 9, there is obtained a mixture consisting chiefly ofbis(acid phthalate), bis( acid maleate), and mixed acid phthalateacidmaleate esters.

EXAMPLE l1 Bis(acid succinate) of 4-[1-(2-hydr0xyethyl)benzimidazol-Z-yl] -4-{1-[2-(2hydroxyethoxy)ethyl1ben2imidazol-2-yl}stilbene A mixture of 8.0 g. of4-[1-(Z-hydroxyethyl)benzimidazol-2-yl] -4-1-[2- (Z-hydroxyethoxy)ethyl] benzimidazol-2- yl stilbene, 4.0 g. of succinic anhydride, 25 ml.of dimethyl sulfoxide, and 3 ml. of pyridine was heated at 100-120 C.for thirty minutes. The reaction mixture was mixed with a solution of5.6 ml. of concentrated hydrochloric acid in 400 ml. of water and theinsoluble precipitate was collected on a filter, washed free ofhydrochloric acid with Water, and dried. There was thus obtained 10.0 g.of product which melted at 124-126 C. It consisted chiefly of thebis(acid succinate) of 4-[1-(Z-hydroxyethyl)benzimidazol-2-yl]-4-{1-[2-(2-hydroxyethoxy)ethyl]benzimidazol-2-yl}stilbene(Formula III:

EXAMPLE 12 Acid dodecylsuccinate of 4- benzimidazol-Z-yl) -4'- [1-(2,3-dihydroxypropyl benzimidazol-Z-yl] stilbene Interaction of 25 g. of4-(benzimidazol-2-yl)-4'-[l- (2,3-dihydroxypropyl)benzimidazol 2 yl]stilbene (obtained as described in Example 28A of U.S. Patent 2,838,504,issued June 10, 1958) with 14 g. of dodecylsuccinic anhydride, followinga procedure similar to that described above in Example 11, yields theacid dodecylsuccinate of the hydroxy-benzimidazolylstilbene startingmaterial.

EXAMPLE 13 Acid dodecenylsuccinate of 4-[1-(2-hydr0xyethyl)benzimidazol-Z-yl] -4'-{1-[2-(2 hydroxyethoxy)ethyl]b'enzimidazol-2-yl}stilbene 27.1 g. of4-[1-(2-hydroxyethyl)benzimidazol-2-yl]- 4'-{1 [2 (2hydroxyethoxy)ethyl] benzimidazol-2-yl}- stilbene, 13.3 g. ofdodecenylsuccinic anhydride, 100 ml. of dimethyl sulfoxide, and ml. ofpyridine were heated together at 100l20 C. for thirty minutes. Thereaction mixture was mixed with a solution of 17 ml. of concentratedhydrochloric acid in 1000 ml. of water. The insoluble precipitate wascollected on a filter, washed free of hydrochloric acid with water, anddried. There was thus obtained 40.0 g. of product which melted at 150 C.with evolution of gas. It was a mixture which consisted chiefly of monoacid dodecenylsuccinates of 4-[1- (Z-hydroxyethyl benzimidazol-Z-yl]-4-{ 1- [2- Z-hydroxyethoxy)ethyl]benzimidazol 2 yl}stilbene(derivatives where in Formula II only one of the hydroxylic hydrogens isreplaced by the radical unreacted hydroxy-benzimidazolylstilbene and ofthe hiscation Serial No. 575,353, filed April 2, 1956,

1G (acid dodecenylsuccinate). The product was soluble in alkalineethanol.

EXAMPLE 14 27.2 g. of 4-[1-(2-hydroxyethyl)benzimidazol-Z-yl] -4- {1-[2(2 hydroxyethoxy)ethyl]benzimidazol 2 yl}- stilbene, 16.7 g. of1,2-cyclohexanecarboxylic anhydride, ml. of dimethyl sulfoxide, and 10ml. of pyridine were heated together at 100120 C. for thirty minutes.The reaction mixture was mixed with a solution of 17 ml.- ofconcentrated hydrochloric acid in 1000 cc. of water. The insolubleprecipitate was collected on a filter, washed free of hydrochloric acidwith water, and dried. There was thus obtained 23.0 g. of product whichmelted with decomposition at -167 C. It consisted chiefly of thebis(acid 1,2-cyclohexanedicarboxylate) of4-[1-(2-hydroxyethyl)benZimidazol-2-yl] 4 {1[2-(2-hydroxyethoxy)ethyl]benzimidazol-Z-yl}stilbene (Formula III:

dilute aqueous ammonia solution and was also moderate.- ly soluble inwater.

EXAMPLE 15 Acid phthalate of 4-( benzimidazol-Z-yl )-4- [1-(2-hydroxy-Z-sulfopropyl) benzimidazol-Z-yl] stilbene When 27.5 g. of4-(benzimidazol-2-yl)-4-[1-(2-hydroxy-2-sulfopropyl)benzimidazol-Z-yl]stilbene (obtained by acidification of the sodium salt disclosed inExample 25 of U.S. Patent 2,838,504, issued June 10, 1958) is treatedwith 7.5 g. of phthalic anhydride by a procedure similar to thatdescribed in Example 3 above, there is obtained the acid phthalate ofthe hydroxy-benzimidazolylstilbene.

When the carboxy-esters described in the foregoing examples aredissolved in aqueous media, the solutions thus obtained fluoresceblue-white under ultraviolet light and show a wide range of absorptionin the ultraviolet region. By incorporating the products into soaps andanionic and non-ionic detergents, there were obtained compositionshighly useful, for example, for whitening white fabrics of cotton,nylon, and cellulose acetate. The preparation of compositions containingthese carboxyesters can be carried out in a manner similar to thatdescribed for the benzimidazolylstilbenes in U.S. Patent 2,838,504,issued June 10, 1958. Thus, for instance, in the preparation ofcompositions comprising 0.02-0.5% by weight of the above-describedcarboxy-esters, the following procedure was used. A solution of thecarboxy-ester in dilute aqueous ammonia solution was added inappropriate amount to aqueous solutions of soap (for example a soapconsisting of four parts by weight of the sodium salts of the C C fattyacids derived from tallow), of synthetic anionic detergents (forexample, (1) 21.8% of a mixture of sodium lauryl sulfate and sodiumdodecylbenzenesulfonates, 18.2% of sodium sulfate, and 60% of sodiumtriphosphate and (2) 19.1% of sodium dodecylbenzenesulfonates, 15.6% ofsodium sulfate, 55.0% of sodium triphosphate, and 10.3% of sodiumcarbonate), and of non-ionic detergents (for example,tert-dodecylmercaptopolyethoxyethanol, Nonic 218). The compositions thusobtained were found to impart a blue-white hue to white fabrics ofcotton, nylon, and cellulose acetate, for instance.

This application is a division of my co-pending applinow U.S. Patent2,878,248, issued March 17, 1959.

11 I claim: 7

i 1; A detergent composition comprising a detergent selected from thegroup consisting of water-soluble soaps, water-soluble non-soapsynthetic organic anionic detergents, and water-soluble syntheticorganic non-ionic detergents and dissolved therein 0.02-0.5% by weightof a carboxy-ester having the structural formula where R R R and R areradicals of the class consisting of hydrogen, lower alkyl containing 1-4carbon atoms, lower alkoxy containing 1-4 carbon atoms, and halo, Z is aradical of the class consisting of hydrogen, lower alkyl containing 1-6carbon atoms, carboxy-lower alkyl containing 2-6 carbons atoms,cyano-lower alkyl containing 3-6 carbon atoms, allyl, methallyl,monocyclic aralkyl containing 7-11 carbon atoms, acyloxyloweralkylwherein lower alkyl contains 2-6 carbon atoms, 2-acyloxy-3-sulfopropyl,and 'acyloxy-oiiaalkyl wherein oxaalkyl contains 3-15 carbon atoms, andZ is a radical of the class consisting of acyloxy-iower alkyl whereinlower alkyl contains 2-6 carbon atoms, 2-acyloxy-3-sulfopropyl, andacyloxy-oxaalkyl wherein oxaalkyl contains 3-15 carbon atoms, saidacyloxy being defined in each instance in the definitions of Z and Z bythe formula HOC-ACOO- where A is the residue of an acid of the groupconsisting of aromatic hydrocarbon-1,Z-dicarboxylic acids and aromatichalohyclrocarbon-1,2-dicarboxylic acids containing 8-20 carbon atoms,aliphatic hydrocarbon-1,2-dicarboxylic acids containing 4-22 carbonatoms, and cycloaliphatic hydrocarbon-1,Z-dicarboxylic acids containing7-8 carbon atoms.

2. A detergent composition comprising a water-soluble synthetic organicanionic detergent and dissolved therein 0.02-0.5% by weight of acarboXy-ester having the structural formula 3. A detergent compositioncomprising a water-soluble synthetic organic anionic sulfonateddetergent and dissolved therein 0.02-0.5% by weight of a carboxy-esterhaving the structural formula G CH- O N 0 CH C 1,

where Z is acyloxy-lower alkyl wherein lower alkyl con- 2 tains 2-6carbon atoms and Z is acyloxy-oxaalkyl wherein oxaalkyl contains 3-15carbon atoms, said acyloxy being defined in each instance in thedefinitions of Z and Z by the formula HOOCACOO where A contain 6-18carbon atoms and is the residue of an aromatichydrocarbon-1,2-dicarboxylic acid containing 8-20 carbon atoms.

4. A detergent composition comprising a water-soluble synthetic organicnon-ionic detergent and dissolved therein 0.02-0.5% by weight of acarboxy-ester having the structural formula N i Z where Y ishydroxy-lower alkyl containing 2-6 carbon atoms and Y ishydroxy-oxaalkyl containing 3-15 carbon atoms.

6 A detergent composition comprising a water-soluble 7 synthetic organicanionic detergent and dissolved therein 1 0. 02-0.05% by weight of anacid maleate of a hydroxybenzimidazolylstilbene having the structuralformula where Y is hydroxy-lower alkyl containing 2-6 carbon atoms and Yis hydroxy-oxaalkyl containing 3-15 carbon atoms.

7. A detergent composition comprising a water-soluble synthetic organicanionic detergent and dissolved therein 0.02-0.05% by weight of an acidphthalate of a hydroxylaenzirnidazolylstilbene having the formula whereY is hydroxy-oxaalkyl containing 3-15 carbon atoms.

8. A detergent composition comprising a water-soluble synthetic organicanionic detergent and dissolved therein 0.02-0.05% by weight of an acidphthalate of 4-(benzimidazol 2 yl)-4-{1-[2 hydroxy-3-(2,3dihydroxypropoxy) propyl 1 benzirnidazol-2-yl}stilbene.

9. A detergent composition comprising a water-soluble synthetic organicanionic detergent and dissolved therein 0.02-0.05 by weight of abis(acid halophthalate) of 4 [1 (2hydroxyethyl)benzimidazo1-2-y1]-4-{1-[2-(2- hyroxyethoxy) ethyl]benzimidazol-Z-yl} -stilbene.

10. A detergent composition comprising a watersoluble synthetic organicnon-ionic detergent and dissolved therein 0.02-0.05% by weight of anacid phthalate of a hfi'adroxy-benzimidazolylstilbene having thestructural '14 where Y is hydroxy-lower alkyl containing 2-6 carbonatoms and Y is hydroxy-oxaalkyl containing 3-15 carbon atoms.

11. A detergent composition comprising a watersoluble synthetic organicnon-ionic detergent and dissolved therein 0.02-0.05 by weight of an acidmaleate of a hYdl'OXYnbBllZiIDidfiZOlYlStflbCflG having the structuralformula o O I] in 0.02-0.05 by weight of an acid phthalate of ahydroxy-benzimidazolylstilbene having the formula where Y ishydroxy-oxaalkyl containing 3-15 carbon atoms.

References Cited in the file of this patent UNITED STATES PATENTS2,488,094 Graenacher et al. Nov. 15, 1949 2,515,173 Ackermann et a1 July18, 1950 2,624,710 Thomas Jan. 6, 1953 2,667,458 Adams "a- Jan. 26, 1954FOREIGN PATENTS 588,972 Great Britain June 9, 1947 UNITED STATES PATENTOFFICE CERTIFICATE OF CORRECTION Patent No 2,937,997 May 24 1960 NathanN. Crounse I H It is herebjr certified that error appears in the-printedspecification of the above numbered patent requiring correction and thatthe said Letters Patent should read as corrected below.

Column 7, line 67 for [Z-hydroxyethoxy)ethylj" read[2-(2-hydroxyethoxy)ethyl] Signed and sealed this 6th day of Decernlber1960.

(SEAL) Attest:

KARL H. AXLINE ROBERT C.'W-ATSON Attesting Ofiicer Commissioner ofPatents

1. A DETERGENT COMPOSITION COMPRISING A DETERGENT SELECTED FROM THEGROUP CONSISTING OF WATER-SOLUBLE SOAPS, WATER-SOLUBLE NON-SOAPSYNTHETIC ORGANIC ANIONIC DETERGENTS, AND WATER-SOLUBLE SYNTHETICORGANIC NON-IONIC DETERGENTS AND DISSOLVED THEREIN 0.02-0.5% BY WEIGHTOF A CARBOXY-ESTER HAVING THE STRUCTURAL FORMULA